Robert, the vulnerability of the tracta joints is generally caused by complete absence of lubrication. Like the Ferret, oil needs to be pumped through the outer tracta housing, into the inner tracta until it appears at the level plug on the diff housing. All too often the oil input was just used as a grease nipple with poor results.
Are you thinking of Archie Marshall? He imported all the Champs etc back when they were released from the British army, into WA, when he closed up the remainder parts wise was sold to Altmanns at Stawel (Vic).
Aust. Humber chassis start at 630001, yours being the 9th, FYI it was the also the 4th one to be given it's ARN.
One rear tail light, one brake light, both on the drivers side, a red reflector each side that appear to have been retro fitted as positions vary. No indicators.
Next time your trawling the net, Paul Handel has a terrific article on the Humber's introduction to Australia:
http://anzacsteel.hobbyvista.com/oth...rtruckph_1.htm
Rich.